一开始遇到array_multisort这个函数时,看手册怎么就是看不懂,很不理解。后来在网上看了很多的例子才慢慢理解一点。现在记下来,留着用。
一,一维数组排序
$a=array("Dog","Cat","Horse","Bear","Zebra");
array_multisort($a);
print_r($a);
结果:
Array(
[0] => Bear
[1] => Cat
[2] => Dog
[3] => Horse
[4] => Zebra)
上面就是按照普通的字母升序排列(A,B,C,d ...),没什么好讲的
二,多个一维数组排序
$ar1 = array(22,12,3);
$ar2 = array(1,3,7);
array_multisort($ar1, $ar2);
echo '<pre>';
print_r($ar1);
print_r($ar2);
结果:
Array(
[0] => 3
[1] => 12
[2] => 22
)
Array
(
[0] => 7
[1] => 3
[2] => 1
)
$ ar1和$ ar2的数据可以看成一个表如下:
$ ar1和$ ar2分别为列名,然后如sql语句一样select * from table order by $ ar1 asc,$ ar2 asc排序即可
三,多维数组排序
通常我们从数据库取出来的
$data=array(
array('id' => 67, 'score' => 20,'name'=>'小明'),
array('id' => 86, 'score' => 10,'name'=>'小红'),
array('id' => 85, 'score' => 60,'name'=>'小花')
);
foreach ($data as $key => $row) {
$id[$key] = $row['id'];
$score[$key] = $row['score'];
}
array_multisort($id, SORT_ASC, $data);
echo "<pre>";
print_r($data);
结果:
Array
(
[0] => Array
(
[id] => 67
[score] => 2
[name] => 小明
)
[1] => Array
(
[id] => 85
[score] => 6
[name] => 小花
)
[2] => Array
(
[id] => 86
[score] => 1
[name] => 小红
)
)
此时,把ID,得分,名字看成列名称如图
如果想按照某个字段排序,先循环获取到所有该字段的值形成一个数组,然后按照该字段排序即可。然后如sql语句一样select * from table order by $ id asc排序即可